This is the problem I have. Given a list xList = [9, 13, 10, 5, 3] I would like to calculate for sum of each element multiplied by subsequent elements sum([9*13, 9*10, 9*5 , 9*3]) + sum([13*10, 13*5, 13*3]) + sum([10*5, 10*3]) + sum ([5*3]) in this case the answer is 608. Is there a way to do this perhaps with itertools or natively with numpy? Below is a function I came up with. It does the job but it is far from ideal as I would like to add other stuff as well. def SumProduct(xList): ''' compute the sum of the product of a list e.g. xList = [9, 13, 10, 5, 3] the result will be sum([9*13, 9*10, 9*5 , 9*3]) + sum([13*10, 13*5, 13*3]) + sum([10*5, 10*3]) + sum ([5*3]) ''' xSum = 0 for xnr, x in enumerate(xList): #print xnr, x xList_1 = np.array(xList[xnr+1:]) #print x * xList_1 xSum = xSum + sum(x * xList_1) return xSum Any help appreciated. N.B: In case you wonder, I am trying to implement Krippendorf's alpha with pandas Continue reading...
